Multiple fusible connector



INVENTOR.

ATTORNEY.

D832. 22, HHK M LE MULTIPLE FUSIBLE CONNECTOR- Filed sept. 3o, 1939' lilllll Patented Dec. 22, 1942 UNITE STATES iutTNT OFFICE MULTIPLE FUSIBLE CONNECTOR Marvin Lee, Rye, N. Y., assignor to Burndy Engineering Company, Inc., a corporation of New York 5 Claims.

This invention relates to electrical connectors provided with fusible elements, and more particularly to multiple electrical insulated connectors, for conducting current from main to branch conductors, having fusible elements for protecting the insulation of the conductors used for underground secondary network systems.

It is known that considerable economy can be had in forming the fusible elements out of the same piece of metal forming the body of the connector or a part thereof. ordinarily, that if there is a fault in one cable and only one of the fusible elements melts, the entire connector assembly must be discarded, this is not a serious disadvantage because the number of faults are relatively few, so that the economy of making all the multiple fusible connectors integral with the connector body, more than compensates for the extra expense of replacing a few multiple fusible connectors.

As for example, where three branch lines are connected to a main line, a connector having four fusible elements would normally be provided.

I have found that a reserve of one or more fusible elements will provide means for a rapid continuation of the service of any line connected to a fusible element that is blown, without discarding the entire connector.

An object of my invention, therefore, is to provide a connector of the aforesaid type with a bank of reserve integral fusible elements not adapted for immediate use but designed to be placed into general use in the event one of the fusible elements in general use is blown The provision of such reserve fusible elements, have further found, necessitates the use of readily removable sections of insulation, exposing the ends of the fusible elements for connection to the branch conductors previously attached tc blown fusible elements, which readily removable sections of insulation, when in position, render the insulation covering the connector, moisture proof and completely insulated.

Thus another object consists in the provision of these aforesaid readily removable sections normally sealing unused fusible elements.

A further object consists in the replacement of these readily removable sections back in the insulating jacket to seal the ends of fusible elements that have been blown to keep the connector body completely sealed and insulated.

In the event all the connections are, or have been in use, and one of the elements should thereafter fuse, I have devised a method of re- While this means placing the fused element made integral with the connector, with replaceable fusible elements to be connected with the projecting stem of the connection. This results in a further economy when replacing the fusible elements, and accordingly is an additional object of my invention.

The fusible elements are enclosed within a heat and electrical insulating receptacle for preventing the flow of heat, metal, and/or current from the fused elements. These receptacles must have sufficient structural strength to hold the two ends of the fusible elements in position when fused. In addition the connections must be made to the ends of the elements in a manner which will produce proper electrical contact.

A further object of my invention, therefore, is to provide means for obtaining maximum proper eiectrical connection of the cable connection and the fusible elements while insuring that the elements when fused, will not loosen the supporting structure.

I accomplish these and other objects and obtain my new results, as will be apparent from thel device described in the following specification and claims, and illustrated in the accompanying drawing, in which:

Fig. l is a side view of a part of my connector' with some of the projecting connections sectioned to indicate their construction.

Fig. 2 is a sectional view of my connector taken along the line 2--2, and in the direction indicated by the arrows.

3 is a side View of the connector with three out of the six possible connections, in use.

Fig. 4 is a plan View of my replaceable fusible element.

Fig. 5 is a side view of a modified connection for a replaceable element.

Referring more particularly to the drawing, reference numeral it, designates the entire connector, comprising a metallic body section Il, which may consist of strips l2, or a solid bar, to which the fusible elements are integrally attached or formed.

An insulating jacket i3, made of insulating material and preferably made of resilient rubber completely encloses the body section.

Extending from the body section Il, are the fusible elements I4, consisting of sheet metal stampings, having a reduced central section I5, of a width, thickness.v and composition, determined by the desired fuse characteristics.

The fusible elements are spaced an appropriate distance from each other to provide proper clearance when assembling the conductors thereto,

and to accommodate heat proof enclosures II, used to confine the arc which results when a fusible section blows This not only prevents the arc from damaging the insulation of the connection, it also restrains the products of the arc, such as molten copper, copper vapors, etc. In addition, barriers I1 are located in the enclosure to prevent the arc from striking any molten copper which might accumulate in a pool to the end masses of the fusible connectors. The heat-proof enclosures may be made of a cement and asbestos composition or any other type of suitable material.

As shown in Fig. 2, the fusible elements are provided with apertures i8 and I9 for entrances of bolts 2G passing through corresponding countersunk perforations 2l in the two halves 22 of the heat-proof enclosures I6.

Thus the two halves of the enclosures are each attached to the two ends of the fusible elements and are locked into position thereon by nuts 23.

A terminal connector 25 with extending plate 26 contains perforations 2l and 23. The bolt 2li passes through aperture 28, to lock the terminal to the enclosure. A contact boit passing through aperture 30 in the extending end of the fusible element, is attached to the terminal. plate through apertures 2l which is threaded for such engagement. Thus a pressure is applied to the fusible element, and terminal plate, sufficient to insure maximum electrical conductivity, without passing through the walls of the enclosure and applying a corresponding pressure thereto.

The conductors E2 with insulation 3S, are exposed for a short distance and inserted .into the terminal connector 25. Any type of terminal connector` may be used, the particular type illustrated, consisting of a split flexible compressing cone 34, forced into the tapered recess 35, by bolt 36, centrally apertured to receive the conductor.

The insulating jacket I3 may extend over the enclosures 22 and terminal connector *25, and may be rolled back when the connections are made. I prefer however to use separable sections 3l of tubular resilient material. These are made seal tight to the main body of the insulating jacket I3, by overlapping the ends, as shown in Figs. l to 3, and applying cement thereto, or pressure rings, or any other well known expe The reserve units 38 are provided with caps 39 which may be readily severed from their separable tubular section fill, by cutting through the partially detached material at di, and removed for inserting a conductor therethrough.

These reserve units are preferably provider. with terminal connectingr means complete. or in part, so that the heat-resisting enclosures Z2, need not be removed in order to apply a conductor thereto.

Should an element fuse and no reserve element remain, a further method of continuing the service is possible. The fused element may be filed away to some point, preferably shoulder` dii, and a separable element lll attached thereto, having cut-out portions 42 at each end, for insertion of the bolts 2l), which may be tightened to support the separable element and the enclosing receptacle in position.

As shown in Fig. 5, the separable fusible element 43 is shown with apertures il@ and at each end thereof for electrical conne-cti n by bolts 45 to the terminal plate of the connector 4l, and the remaining section lflil.

The bolts 49, hold the enclosures 5i? together about the fusible element. With this arrangement, the pressure necessary for establishing proper contact between the fusible element and the connector terminal 41 and section 48, need not be applied to the softer materials of which the enclosure may be made.

I have by the foregoing arrangement secured the economies resulting from a connector formed integrally' with the fusible elements, together with advantages obtained by the use of replaceable fusible elements.

An important additional advantage is obtained by the uses of individual heat resistance jackets for each of the fusible elements, and removable insulating covers therefor which may be sealed, thus enabling individual connections to be made and elements replaced without disturbing the remaining connections.

I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out .in other ways withoutl departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalities coming within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

What I claim and desire to secure by Letters Patent is as follows:

l. A multiple electrical connector for joining main to branch conductors comprising a metallic section of unitary construction; a plurality of fusible elements extending therefrom; an individually removable l'ieat-resistant enclosure for each of said fusible elements; and means for attaching an electrical conductor to each of said fusible elements.

2. A multiple electrical connector for joining main to branch conductors comprising a metallic section of unitary construction; a plurality of fusible elements extending therefrom; an individually removable heat-resistant enclosure for each of said fusible elements; means for attachi ing an electrical conductor to each of said fusible elements; and insulation completely covering said metallic section, fusible elements, and heat-resistant enclosures, having removable sections of insulating material, at the end of each fusible element for connecting the conductors to said fusible elements.

3. A multiple electrical connector for joining main to branch conductors comprising a metallic section of unitary construction; a `plurality of replaceable fusible metallic elements extending therefrom; an individually removable heat-resistant enclosure for each of said fusible elements; means for attaching an electrical conductor to each of said fusible elements; and insulation completely covering said metallic section, fusible elements, and heat-resistant enclosures.

4. A multiple electrical connector for joining main to branch conductors comprising a metallic section of unitary construction; a plurality of fusible elements extending therefrom; a heat-resistant enclosure for said elements, means for attaching an electrical conductor to each of said elements; and insulation completely covering said metallic section, heat-resistant enclosure and fusible elements, provided with openings and readily removable sections of insulating material covering the openings for a plurality of conductors to be immediately connected to a corresponding number of fusible elements, with the `remaining fusible elements completely covered by said inl;

sulation.

5. A multiple electrical connector for joining main to branch conductors comprising a metallic section of unitary construction; a plurality of fusible elements extending therefrom having 10 

